Pet blow moulding machines

ABSTRACT

A blow moulding machine for blow moulding a container having an integrally formed handle; said container blow moulded from a previously injection moulded preform; said preform comprising a body portion and said integrally formed handle; said machine including a preform loading station at which said preform is oriented by a preform orienting apparatus.

This invention relates to a container with an integrally connectedhandle, preform from which the container is biaxially blown and a methodof manufacture thereof and more particularly to a preform and resultingcontainer having a handle integrally connected at at least two separatepoints.

BACKGROUND OF THE INVENTION

Attempts have been made to incorporate integral handles in PET and likeinjection blow moulded containers—for example see U.S. Pat. No.4,629,598 to Thompson, assigned to Tri-Tech Systems International, Inc.The parison or preform from which the handled bottles of U.S. Pat. No.4,629,598 are produced is illustrated in FIG. 1. To date, however,attempts to produce a practical, mass produced version of thisarrangement have been unsuccessful. Instead, the best that appears tohave been done in commercial practice is an arrangement whereby theblown containers are arranged to accept a clip on or snap on handle in aseparate production step after the container itself is formed. See forexample WO82/02371 and WO82/02370, both to Thompson.

Injection-stretch-blow moulding is a process in which the parison isstretched both axially and radially, resulting in biaxial orientation.

Biaxial orientation provides increased tensile strength (top load), lesspermeation due to tighter alignment of the molecules, and improved dropimpact, clarity, and lightweighting of the container.

Not all thermoplastics can be oriented. The major thermoplastics usedare polyethylene terephthalate (PET), polyacrylonitrile (PAN), polyvinylchloride (PVC), and polypropylene (PP). PET is by far the largest volumematerial, followed by PVC, PP, and PAN.

The amorphous materials, e.g., PET, with a wide range ofthermoplasticity are easier to stretch-blow than the partiallycrystalline types such as PP. Approximate melt and stretch temperaturesto yield maximum container properties are:

Melt, Stretch, Material Degrees C. Degrees C. PET 280 107 PVC 180 120PAN 210 120 PP 240 160

There are basically two types of processes for stretch-blow moulding: 1)single-stage in which preforms are made and bottles blown on the samemachine, and 2) two-stage in which preforms are made on one machine andblown later on another machine.

Single-stage equipment is capable of processing PVC, PET, and PP. Oncethe parison is formed (either extruded or injection moulded), it passesthrough conditioning stations which bring it to the proper orientationtemperature. The single-stage system allows the process to proceed fromraw material to finished product in one machine, but since toolingcannot be easily changed, the process is best suited for dedicatedapplications and low volumes.

Oriented PVC containers most commonly are made on single-stage,extrusion-type machines. The parison is extruded on either single- ordouble-head units. Temperature conditioning, stretching, and threadforming are done in a variety of ways depending on the design of themachine. Many of the processes presently in use are proprietary.

Many oriented PET containers are produced on single-stage machines.Preforms are first injection moulded, then transferred to a temperatureconditioning station, then to the blow moulding operation where thepreforms are stretch-blown into bottles, and finally to an ejectstation.

With the two-stage process, processing parameters for both preformmanufacturing and bottle blowing can be optimized. A processor does nothave to make compromises for preform design and weight, productionrates, and bottle quality as he does on single-stage equipment. He caneither make or buy preforms. And if he chooses to make them, he can doso in one or more locations suitable to his market. Both high-outputmachines and low output machines are available. Heretofor two stageextrusion-type machines generally have been used to make oriented PPbottles. In a typical process, preforms are re-extruded, cooled, cut tolength, reheated, stretched while the neck finish is being trimmed, andejected.

It is an object of the present invention to produce a practical, readilyimplementable injection, stretch blow moulded container made from anorientable plastics preform material incorporating a handle joined in aloop at at least two points to the preform.

SUMMARY OF THE INVENTION

In a first broad form of the invention there is provided a preform for acontainer comprised of orientable plastics material and arranged so thatthe resultant blown container will include a handle or like supportstructure; said preform comprising a moulded structure having a neckportion and an expandable portion below the neck, at least one loop oforientable plastics material integrally connected at least a first endto a respective first location on said preform which when the containeris formed constitutes said handle.

In another broad form of the invention there is provided a method offorming a container having an integral handle; said method comprising:

-   -   (a) forming a preform having a neck portion and an expandable        portion below the neck portion, said preform having at least one        loop of orientable plastics material integrally connected at        least a first end to a respective first location on said        preform, and    -   (b) performing a blow moulding operation on said preform to        expand the expandable portion to form the body of the container.

Preferably, the neck portion includes a locating ring above theexpandable portion.

Preferably, said container is formed from said preform in a two stageoperation.

Preferably, said at least one loop of orientable plastics material isintegrally connected at said first end to said first location and at asecond end at a second location on said preform.

Preferably, the handle allows at least two fingers of the adult humanhand to pass therethrough.

Preferably, the loop is formed so as to have an I-shaped cross-sectionat least throughout that portion of the stem where it projects from theexternal side of said tube.

In a further broad form of the invention there is provided a parison orpreform as claimed in claim 1 for an injection stretch blow mouldingprocess, said parison formed by an injection process including twoseparate points of injection.

Preferably, a first point of injection permits injection of non-recycledPET or like plastics material.

Preferably, a second point of injection permits injection of PET or likeplastics material incorporating at least a portion of recycled material.

Preferably, said first point of injection is for the formation of thatpart of the preform which will be stretched during a stretch blowmoulding operation on the preform.

Preferably, said second point of injection is for the formation of thoseparts of said preform which will remain unexpanded or substantiallyunexpanded in a stretch blow moulding operation on said preform.

In still a further broad form of the invention there is provided acontainer manufactured from a two stage injection stretch blow mouldingprocess, said container including a graspable handle integrally affixedat at least a first point to said container so as to form an areabetween the handle and the container and through which the fingers of ahuman hand may be passed.

Preferably, said first point of connection comprises an integralconnection between the handle and the neck portion of the container andis formed in a first stage of said two stage process.

Preferably, said graspable handle is integrally affixed at said at leasta first point and a second point of interconnection to said container soas to form an enclosed area between the handle and the container andthrough which the finger of a human hand may be passed.

Preferably, said second point of connection is located on an expandableportion of said container.

Preferably, said second point of interconnection is located on a lowerneck portion of said container at a substantially non-expanding part.

Preferably, said first and second points of connection are located on asubstantially non-expanding part of said container.

Preferably, the container includes an elongated substantiallynon-expanding neck portion to which said loop is affixed.

Preferably, the preform further includes a locating ring immediatelybelow which is a first non-expanding region and below which is a secondnon-expanding region.

Preferably, the first non-expanding region is formed so as to beslightly raised or otherwise differentiated from the expandable portionof said preform.

Preferably, the second non-expanding region is not differentiated fromthe expandable portion of said preform.

Preferably, the loop includes a first rib integrally moulded therewith.

Preferably, said loop includes a second rib integrally moulded with andextending from said second non-expanding region.

Preferably, the preform further includes a rib connector integrallymoulded with and extending from first non-expanding region and forming acontinuous connection between said first rib and said second ribthroughout the length of said loop.

Preferably, said second non-expanding region forms part of a temperaturetransition zone.

The preform of any one of claims 20 to 26 and wherein said firstnon-expanding region forms part of said temperature transition zone.

Preferably, deformation of said temperature transition zone takes placeduring a stretch blow moulding process.

Preferably, the preform is manufactured by a two stage injectionmoulding process wherein material is injected at different locations inthe die to form a preform adapted to be composed from more than one typeof material.

Preferably, during at least one stage of said two stage process an innerwall and outer wall of said preform is formed, said inner wall adaptedto be made from a different material from said outer wall.

In a further broad form of the invention, there is provided a containerstretch blow moulded from the preform of any one of claims 20 to 30.

In yet a further broad form of the invention there is provided a methodof production as a two step process of an integral handle PET containerfrom a preform which has a loop of orientable plastics material at leastone loop of orientable plastics material integrally connected at least afirst end to a respective first location on said preform; said methodincluding the step of shielding said loop of said preform duringpreheating of said preform preparatory to a stretch blow moulding step.

Preferably, said at least one loop of orientable plastics material isintegrally connected at said at least a first end to said first locationand at a second end to a second location on said preform.

Preferably, said at least a first end and said second end aresubstantially supported in a mould cavity against movement during thestretch blow moulding operation.

In still another broad form of the invention there is provided acontainer comprised of biaxially orientable plastics materialmanufactured from a two stage injection stretch blow moulding process;said two stage process comprising a first stage in which a preform ismanufactured and a second stage in which said preform is reheated andbiaxially stretched to form said container; said container including agraspable handle integrally affixed at at least a first point ofconnection to said container so as to form an area between said handleand said container and through which at least two fingers of a humanhand can pass.

Preferably, said graspable handle is integrally affixed at said at leasta first point of interconnection and a second point of interconnectionto said container so as to form an enclosed area between the handle andthe container and through which the finger of a human hand may bepassed.

Preferably, said first point of interconnection and said second point ofconnection comprises an integral interconnection between the handle andthe container and is formed in said first stage of said two stageprocess.

Preferably, the container further includes a locating ring at a neckportion thereof.

Preferably, the container further includes a first non-expanding regionimmediately below said locating ring.

Preferably, the container of further includes a second non-expandingregion below said first non-expanding region.

Preferably, said first non-expanding region is formed so as to beslightly raised or otherwise differentiated from that portion of saidcontainer which is fully biaxially oriented during said second stage ofsaid two stage process.

Preferably, said second non-expanding region is not differentiated fromthat portion of said container which is fully biaxially oriented duringsaid second stage of said two stage process.

Preferably, minor expansion of said second non-expanding region takesplace during said second stage of said two stage process.

Preferably, said handle includes a first rib integrally moulded with andextending from said locating ring.

Preferably, said handle includes a second rib integrally moulded withand extending from said second non-expanding region.

Preferably, the container further includes a rib connector integrallymoulded with and extending from said first non-expanding region andforming a continuous connection between said first rib and said secondrib throughout the length of said handle.

Preferably, said second non-expanding region forms part of a temperaturetransition zone.

Preferably, said first non-expanding region forms part of a temperaturetransition zone.

Preferably, deformation of said temperature transition zone takes placeduring a stretch blow moulding process.

Preferably, the container is manufactured by said two stage injectionmoulding process and wherein material is injected at different locationsduring formation of said preform during said first stage of said twostage process whereby said container can be composed from more than onetype of material.

Preferably, during said first stage of said two stage process an innerwall and outer wall of said preform is formed, said inner wall made froma different material from said outer wall.

Preferably, the container further includes a discontinuity region asdefined in the specification.

Preferably, said discontinuity region lies in a plane which lies at anacute angle to the horizontal, said discontinuity region extendingsubstantially throughout the circumference of said container.

Preferably, said discontinuity region at its point closest to saidhandle is located between a first end and a second end of said handle.

In, a further broad form of the invention there is provided a preformfrom which the container of any one of claims 36 to 55 is shown in a twostage process, said preform including more than one wall profile.

Preferably, said preform has a first wall profile closest to its neckfollowed by a second wall profile immediately there below and separatedtherefrom by a first transition zone.

Preferably, said preform further includes a third wall profileimmediately below said second wall profile and separated therefrom by asecond transition zone.

There is further provided an injection machine for the manufacture of aparison or preform according to claim 1 or any one of claims 7 to 11 orany one of claims 21 to 30 in a first stage of a two stage process.

There is further provided a stretch blow moulding machine for themanufacture of a container having an integral handle, said machineoperable according to the method of any one of claims 2 to 6 or any oneof claim 34 or 35.

There is further provided an injection machine for the manufacture ofpreforms having integral handles incorporated therein; said machineincluding moulds having a channel which permits PET material to flowinto a stem portion which constitutes a handle in a container blown froma preform produced by said injection moulding machine.

Preferably, said channel of said mould includes a return portion wherebysaid stem is connected integrally at two points on said preform.

In another broad form of the invention, there is provided a blowmoulding machine for blow moulding a container having an integrallyformed handle; said container blow moulded from a previously injectionmoulded preform; said preform comprising a body portion and saidintegrally formed handle; said machine including a preform loadingstation at which said preform is oriented by a preform orientingapparatus. Preferably, said machine further includes a preform loadingstation and a preform transporting system; said transporting systemincluding a plurality of mandrels; each of said mandrels provide with aheat shield for at least partially covering said integrally formedhandle. Preferably, said preform orienting apparatus is adapted toaligning said integrally formed, handle of a said preform, with saidheat shield of said mandrel; the arrangement being such as to allowinsertion of said handle into said heat shield when said preform isbrought into engagement with said mandrel.

Preferably, said machine further includes apparatus for orienting saidintegrally formed handle of said preform for entry of said preform intoa stretch blow moulding tool of said machine.

Preferably, said loading station includes an infeed rail; said infeedrail supplied with preforms from a preform supply source; an output endof said rail arranged to release individual ones of said preformssequentially to said orienting apparatus.

Preferably, said body portion of said preform is presented to saidorienting apparatus with the axis of said body portion substantiallyvertical.

Preferably, said orienting apparatus includes a cylindrical sleeve fixedrelative to said output end of said infeed rail; said sleeve having anaxis substantially vertical; said axis aligned with an axis of said bodyportion of a said preform when said preform is released from said infeedrail.

Preferably, said sleeve has an internal diameter adapted to allowpassage through said sleeve of said body portion of said preform.

Preferably, said sleeve is provided with a slit in a wall of saidsleeve; said slit having a width sufficient for passage therethrough ofsaid integrally formed handle; said slit extending from a handle inletopening at the upper end of said sleeve to a handle outlet opening at alower end of said sleeve.

Preferably, said upper end of said sleeve is truncated so that at leastportions of said upper edge of said sleeve are at a slope relative tosaid axis of said sleeve.

Preferably, said at least portions of said upper edge of said sleeve arearranged to slope from at least one high point on said upper edge tosaid handle inlet opening.

Preferably, said upper edge is divided into two sloping sections; eachsloping section forming a sloping edge from said at least one high pointto respective first and second sides of said inlet opening of said slit.Preferably, respective said edges of said sloping sections meet saidrespective first side and second sides of said inlet opening in smoothlyrounded corners.

Preferably, said slope of said sloping sections is sufficient to ensuresaid integrally formed handle of a said preform is forced by the weightof said preform to slide downwardly along a said sloping section; saidpreform rotating until said handle is aligned with said slit; saidpreform and said handle then free to fall through said sleeve and saidslit.

Preferably, an indexing table is provided below said orientingapparatus; said indexing table provided with a plurality of nests spacedequally around the periphery of said table; each of said nestssequentially brought into alignment with said axis of said sleeve atsuccessive indexes of said table.

Preferably, each of said nests, when in said alignment with said axis ofsaid sleeve, is arranged to accept and retain a said preform fallinginto a nest from said orienting apparatus; said handle retained in saidnest in an orientation imposed by said slit of said orienting apparatus.

Preferably, a said preform is ejected upwardly from a said nest at asuitable subsequent indexed location of said indexing table; saidpreform brought into engagement with one of a plurality of mandrels of apreform transportation system.

Preferably, each said preform is brought into engagement with a mandrelof said preform transportation system.

Preferably, each of said mandrels is provided with a handle protectionshield; said shield partially enclosing said handle when a said preformis brought into engagement with a said mandrel.

Preferably, said mandrels are equally spaced along a recirculatingconveying system; said conveying system driven incrementally insynchronisation with increments of said indexing table.

Preferably, each of said mandrels of said preform transportation systemis adapted for rotation about the axis of said preform; each of saidmandrels being brought into a predetermined orientation at said suitablesubsequent indexed location of said indexing table such that said handleprotection shield is correctly aligned to accept entry therein of a saidintegrally formed handle of said preform.

Preferably, length of said preform transportation system and saidrotation of said mandrels is arranged so that the handle of each saidpreform is at said predetermined orientation when said preform isreleased from said mandrel.

Preferably, said mandrel and said handle of said preform are rotatedinto said predetermined orientation prior to said mandrel and saidpreform entering said blow moulding tool.

Preferably, said preforms are rotated during transportation by saidpreform transportation system past an array of preform heating elements.

Preferably, said handle and said heat shield are nested in a cavityprovided for said handle and said preform in said blow moulding tool.

Preferably, said handle and said heat shield are nested in separatecavities in said blow moulding tool.

In another broad form of the invention there is provided an apparatusfor orienting a preform for stretch blow moulding a container; saidpreform comprising a substantially cylindrical body with an integrallyattached handle; said apparatus including a sleeve provided with a slitand at least one sloping upper edge; said at least one sloping uppersurface and said slit arranged so as to guide said integrally attachedhandle into alignment with said slit.

Preferably, said preform is dropped into said sleeve; the bore of saidsleeve adapted to accept as a sliding fit said body of said preform; anunderside of said handle coming into sliding contact with a said upperedge.

Preferably, slope of a said sloping upper edge is sufficient to inducerotation of said preform as said handle slides down said sloping upperedge; said rotation causing said integrally attached handle to come intosaid alignment with said slit.

Preferably, said slit is adapted to allow sliding passage of said handlewhen said handle is brought into alignment with said slit.

In another broad form of the invention, there is provided a heat shieldfor the protection of an integrally formed handle of a preform; saidheat shield protecting said handle from excessive heat as a body portionof said preform is pre-heated prior to entry into a stretch blowmoulding tool.

Preferably, said heat shield is attached to a mandrel of a preformtransportation system; said heat shield adapted to at least partiallyenclose said handle.

Preferably, said shield comprises side portions extending substantiallyover opposing sides of said handle; said side portions extending fromopposing edges of a spine element attached to said mandrel; said spineelement conforming to upper portions of said handle.

Preferably, edges of said side portions are shaped to selectivelyprotect interconnection points of said handle from said excessive heat;portions of said, side elements arranged to allow a sufficient gap foradequate heat penetration to a body region of said preform between saidinterconnection points.

In another broad form of the invention there is provide an apparatus forcontrolling the orientation of a mandrel of a stretch blow mouldingmachine; said mandrel adapted for supporting a preform comprising a bodywith an integrally attached handle; said apparatus adapted to lock saidmandrel into an oriented state and unlock said mandrel into a freelyrotating state.

Preferably, said mandrel is one of a plurality of mandrels of a preformtransport system of said blow moulding machine.

Preferably, when said mandrel is in said oriented state said integrallyattached handle may be inserted into a heat shield attached to saidmandrel.

Preferably, when said mandrel is in said oriented state said integrallyattached handle is correctly oriented for entry into a blow mouldingtool of said machine. Preferably, when said mandrel is in said freelyrotating state said mandrel may be driven into rotation by a drivemechanism of said machine engaging a rotation driving sprocket of saidmandrel during a preform preheating stage.

Preferably, said mandrel is provided with spring-loaded pawl; saidspring-loaded pawl adapted to engage with a notch located on a boss ofsaid rotation driving sprocket; said spring-loaded pawl activated anddeactivated by a lever mechanism contacting fixed cams provided atpredetermined locations along said preform transport system.

Preferably, said lever mechanism is activated to set said spring-loadedpawl into a potential locking state at a first of said predeterminedlocations; a rotary drive rotating said sprocket until saidspring-loaded pawl engages said notch.

Preferably, said lever mechanism is activated to retract saidspring-loaded pawl to return said sprocket to said freely rotating stageat a second of said predetermined locations.

In another broad form of the invention, there is provided an apparatusfor controlling the orientation of an integrally formed handle of apreform during a preheating stage of a stretch blow moulding process;said, apparatus including a mandrel provided with a shield forprotecting said handle from excessive heat during said preheating stage.

Preferably, said mandrel is one of a plurality of mandrels attached to atwin-strand conveyor system; each said mandrel rotatably mounted betweenstrands of said twin-strand conveyor.

Preferably, said preform is inserted into said mandrel at a preformloading location such that said handle is located within said shield.

Preferably, said conveyor system extends between said preform loadinglocation and a preform unloading location.

Preferably, each said mandrel is urged into rotation between saidloading location and said unloading location; said rotation derived fromcontact between a toothed pulley of said mandrel and a rack extendingbetween said loading location and said unloading location.

Preferably, said mandrel completes a whole number of rotations betweensaid loading location and said unloading location such that orientationof said shield at said unloading location is substantially identical toorientation of said shield at said loading location. Preferably,orientation of said shield is maintained between the end of said rackbefore said unloading location and the start of said rack after saidloading location; said orientation maintained by a guiding surface ofsaid mandrel maintaining sliding contact with a fixed rail.

In another broad form of the invention there is provided a mandrel forsupport and selective heat shielding of a preform provided with anintegral handle; said mandrel comprising a vertically oriented socketportion and a shield portion depending from said socket portion.

Preferably, said socket portion is adapted to accept insertion andretention therein of a neck portion of said preform; said shield portionadapted to accept insertion and at least partially shield said integralhandle.

Preferably, said socket portion is provided with a resilient plug; saidplug adapted to enter an open neck of said preform when an inverted saidpreform is urged upwardly to engage with said mandrel; said plugentering said open neck as a friction fit sufficient to support theweight of said preform.

In another broad form of the invention there is provided a method forcontrolling a preform for stretch blow moulding a container with anintegrally formed handle; said preform comprising a body portion andsaid integrally formed handle; said preform transferred from a preformsupply source to a blow moulding tool for blowing said container; saidmethod including the steps of:

-   -   a. passing said preform through a preform handle orienting        apparatus,    -   b. transferring said preform to a preform transportation system,    -   c. transferring said preform from said, transportation system to        said blow moulding tool.

Preferably, said method includes the further steps of:

-   -   a. maintaining orientation of said preform handle imposed by        said handle orienting apparatus during said transfer to said        preform transportation system and said transfer to said blow        moulding tool,    -   b. rotating said preforms during transport along said        transportation system past an array of preform heating elements,    -   c. shielding said integrally formed handles from excessive        exposure to heating from said heating elements.

Preferably, said preform handle orienting apparatus comprises acylindrical sleeve provided with a slit along a wall of said sleeve; aninternal diameter of said sleeve allowing passage through said sleeve ofsaid body portion of said perform; width of said slit allowing passagetherethrough of said integrally formed handle.

Preferably, an upper edge of said sleeve is sloped relative to an axisof said sleeve; said upper edge sloping from at least one high point tosaid slit.

Preferably, a said preform is presented to said orienting apparatus withan axis of said body portion substantially aligned with said axis ofsaid sleeve. Preferably, said slope of said upper edge is such as toensure a said handle of a said preform is caused to slide downwardlyalong said slope until said preform and said handle rotate intoalignment with said slit. Preferably, transfer of said preform to saidtransportation system includes the steps of:

-   -   a. receiving a preform passing through said sleeve of said        orienting apparatus into a nest of an indexing table,    -   b. retaining said preform in said nest with said handle retained        in said orientation imposed by said orienting apparatus,    -   c. ejecting said preform from a said nest so as to engage with a        mandrel of said transportation system.

Preferably, each mandrel of said transportation system is provided witha preform handle protection shield; each said mandrel rotated to aposition wherein said protection shield is aligned with said preformhandle when said preform is ejected from a said nest.

Preferably, rotation of each said mandrel is controlled such thatorientation of said handle is correctly aligned for entry into said blowmoulding tool at a point where said preform is released from saidtransportation system.

In another broad form of the invention there is provided a method andapparatus for preheating a preform; said preform comprising a bodyportion and an integrally attached handle; said method including thesteps of:

-   -   a. orienting said preform so as to engage said preform with a        transport system mandrel; said mandrel provided with a shield        substantially covering said handle,    -   b. arranging banks of heating elements into a pattern allowing        for rotation of said handle and said shield,    -   c. setting heat outputs of individual heating elements to        deliver a required distribution of heat density to said body        portion of said preform,    -   d. rotating said preform during a preheating stage as said        transport system carries said preform past said banks of heater        elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of a prior art parison,

FIG. 2 is a side view of a parison incorporating features usable withembodiments of the present invention,

FIG. 3 is a partial side elevational view of a blow moulded PETcontainer formed from a preform usable with one embodiment of theinvention;

FIG. 4 illustrates the steps of formation of a parison usable withanother embodiment of the invention.

FIG. 5A is a side view of a preform according to a further embodiment ofthe invention;

FIG. 5B is a side view of a container formed from the preform of FIG.5A.

FIG. 6 is a side view of a die in open position for manufacture of apreform;

FIG. 7 is the die of FIG. 6 in closed position;

FIG. 8 is a side view of the die of FIGS. 6 and 7 showing the stem ofthe preform located therein,

FIG. 9 is a top view of a two stage injection, blow mould machineadapted to receive preforms and biaxially orient them into blowncontainers according to embodiments of the invention,

FIG. 10 is a side section view of a lifting, lowering and rotatingmechanism for handle covers for use with the machine of FIG. 9,

FIG. 11 is an alternative side section view of the mechanism of FIG. 10,

FIG. 12 is a side section, close up view of the machine of FIG. 9showing a preform with handle cover lowered over the handle portionthereof,

FIGS. 13A, B illustrates first and second side section views of apreform adapted for loading into the machine of FIG. 9,

FIG. 14 is a perspective view of the preform of FIG. 13,

FIG. 15 is a perspective view of a container blown from the preform ofFIG. 14 on the machine of FIG. 9,

FIG. 16 is a plan view of a half mould adapted for blowing preforms onthe machine of FIG. 9,

FIG. 17 is a top view of the mould of FIG. 16 with a preform insertedtherein ready for blowing on the machine of FIG. 9,

FIG. 18 is a bottom view of FIG. 17 with both half moulds in opposedrelationship,

FIG. 19 is a further bottom view of FIG. 17 showing the preform in theposition of FIG. 17,

FIG. 20 is a section view through the half mould of FIG. 16,

FIG. 21 is a section view through the mould of FIG. 16,

FIG. 22 is a side view of the container of FIG. 15 blown in the mould ofFIG. 19 from a preform as illustrated in FIGS. 13 and 14,

FIG. 23 is a detail, side section view of the neck and top handleportion of the container of FIG. 22,

FIG. 24 is a side view of a preform incorporating an enlarged firstnon-expanding region usable with embodiments of the invention,

FIG. 25 is an alternative side view of the preform of FIG. 24,

FIG. 26 is a side view of a container blown from the preform of FIG. 24on the machine of FIG. 9,

FIG. 27 is a perspective view of the preform of FIG. 24,

FIG. 28 is a perspective view of the container of FIG. 26,

FIG. 29 is a side view of yet a further alternative embodiment of apreform incorporating a lengthened or enlarged first non-expanding zoneand adapted for blowing on the machine of FIG. 9,

FIG. 30 is a side view of a container blown from the preform of FIG. 29on the machine of FIG. 9,

FIG. 31 is a plan view of a half mould for blowing the preform of FIG.24,

FIG. 32 is a plan view of the half mould of FIG. 31 with the preform ofFIG. 24 inserted therein ready for blowing on the machine of FIG. 9,

FIG. 33 is a side section view of a container blown in the mould of FIG.32 and

FIG. 34 is a detail side section view of the neck and top handle portionof the container of FIG. 33.

FIG. 35 is a first perspective view of a container usable withembodiments of the invention particularly adapted to resist highinternal pressures,

FIG. 36 is a second perspective view of the container of FIG. 35,

FIG. 37 is a first side view of the container of FIG. 35,

FIG. 38 is a second side view of the container of FIG. 35,

FIG. 39 is a plan view of the container of FIG. 35,

FIG. 40 is a side view of a preform from which the container of FIG. 35can be blown,

FIG. 41 is a perspective view of the preform of FIG. 40,

FIG. 42 is a perspective view of a container with strap connected handleaccording to an embodiment of the invention, and

FIG. 43 is a side view of a preform from which the container of FIG. 42can be blown.

FIG. 44 is a side section view of a preform having a multiple integralconnection handle according to an embodiment of the invention,

FIG. 45 is a side section view of the resulting container blown from thepreform of FIG. 44,

FIG. 46 is a side section view of an alternative embodiment of acontainer having a multiple integral connection handle,

FIG. 47 is a side section view of a preform having a multiple integralconnection handle according to a further embodiment of the invention,

FIG. 48 is a side section view of a, preform having a multiple integralconnection handle according to a further embodiment of the invention,

FIG. 49 is a perspective view of the preform of FIG. 48,

FIG. 50 is a perspective view of a container blown from the preform ofFIG. 48,

FIG. 51 is a top view of the container of FIG. 50, and

FIG. 52 is a bottom view of the container of FIG. 50.

FIG. 53 is a side view of a preform utilised as stock in a stretch blowmoulding machine according to an embodiment of the invention,

FIG. 54 is a side view of a container produced from the stock of FIG. 1on the stretch blow moulding machine according to a first embodiment ofthe invention,

FIG. 55 is a plan view of a stretch blow moulding machine according to afirst embodiment of the invention,

FIG. 56 is a side view of the preform of FIG. 53 being loaded onto atransport mandrel having a nesting shield for transport through themachine of FIG. 55,

FIG. 57 is a side view of the assembly of FIG. 56 passing through aheating phase on the machine of FIG. 3,

FIG. 58 is a side view of the assembly of FIG. 56 being aligned prior toentry into a die on the machine of FIG. 3,

FIG. 59 is a side view of the assembly of FIG. 56 in an initial positionwithin a die on the machine of FIG. 3,

FIG. 60 is a side view of the assembly of FIG. 56 in a blow mouldingposition within the die of FIG. 59,

FIG. 61 is a perspective view of the shield of the assembly of FIG. 56,

FIG. 62 is a perspective view of a 16 cavity preform mould suitable forinjection moulding preforms in a first stage of a modified two stageprocess,

FIG. 63 is a perspective view of a preform produced by the mould of FIG.62,

FIG. 64 is an end view of the mould of FIG. 62 in substantially closedposition,

FIG. 65 is an end view of the mould of FIG. 62 in substantially openposition,

FIG. 66 is a side view, partially cut away of the mould of FIG. 62,

FIG. 67 is an end, partially cut away view of the mould of FIG. 62,

FIG. 68 is an end, partially cut away view of the mould of FIG. 62 insubstantially open condition,

FIG. 69 is an end view of the mould of FIG. 62 showing a preforminjection operation,

FIG. 70 illustrates detail of injector nozzles of the preform unit ofFIG. 62, and

FIG. 71 illustrates the injector nozzle arrangement of in a shut offcondition,

FIG. 72 is a schematic plan view of a stretch blow moulding machine of atwo stage process,

FIG. 73 is a perspective detail view of a preform handle orientingapparatus,

FIG. 74 is a perspective view of an indexing table for transferringoriented preforms to the mandrels of a preheating stage transportsystem,

FIG. 75 is a sectioned view of an oriented preform attached to a mandrelof the preheating stage transport system with the preform handle locatedin a heat shield,

FIG. 76 is an enlarged sectioned side view of the preform and heatshield arrangement of FIG. 75,

FIG. 77 is a preferred arrangement of a bank of heater elements arrangedfor preheating a preform according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First PreferredEmbodiments of a Two Stage Process

FIG. 1 illustrates a prior art preform or parison by way ofintroduction.

FIGS. 2 through to 41 illustrate preform and resulting containers andmethods of manufacture thereof and machinery for manufacture thereofwhich can be adapted according to embodiments of the invention toinclude multiple integral connection of the handle stem or loop to thepreform and resulting container.

In this specification the term “integral connection” or “integrallyconnected” means a connection between the handle and the preform (andsubsequently the corresponding connection on the container blown fromthe preform) which is made from the same material as the handle and thepreform and is formed as an inherent part of an at the same time as thepreform is formed.

All first embodiments of the invention are produced in a two stageprocess.

In particular forms, embodiments are produced in a modified two stageprocess as to be later described.

The two-stage process is the lowest-cost method to produce oriented PETcontainers. The two-stage process, which provides injection moulding ofthe preform and then shipping to blow moulding locations, allowscompanies to become preform producers and to sell to blow mouldingproducers. Thus companies that wish to enter the market with orientedPET containers can minimise their capital requirements. Two-stagestretch-blow moulding also can be used for production of oriented PVCcontainers. Preform design and its relationship to the final containerremains the most critical factor. The proper stretch ratios in the axialand hoop directions are important if the container is to properlypackage its intended product. Exemplary ratios are as follows:

Stretch Orientation Material Ratios Temp. Deg. F. PET 16/1 195-240 PVC 7/1 210-240 PAN  9/1 220-260 PP  6/1 260-280

A container 10 usable with an embodiment of the invention is shown inFIG. 3. It includes a neck 11 and an expanded portion 12.

The neck 11 has a threaded portion 13 and a locating ring 14. Mouldedintegrally with the ring 14 is a stem having a first portion 15 aextending outwardly from the ring 14 and a second portion 15 b soinclined to the first portion 15 a that it is nearly parallel to avertical axis of the container 10. In this instance, the first portion15 a subtends an angle of slightly more than 45° to the wall 20 and thesecond portion subtends an angle of about 20° to the wall 20.

The particular shape of the stem 15 is selected so that when formed as ahandle it may be grasped by fingers of the human hand.

The stem 15 terminates in a stem end 16 which faces generally downwardlyin the general direction of closed end of the container 10.

In this instance, the stem 15 is of I-shaped cross-section to combatunwanted effects arising at or near junction 17 of stem 15 with the ring14 following a blowing operation on the preform 10.

These unwanted effects particularly include stress effects and airinclusions resulting from non-uniform cooling through preform volumes ofdiffering cross-section.

In this arrangement, the preform is made from PET and is preparedutilizing a heated mould.

In order to produce the container 10, the parison or preform 26 (seeFIG. 2) according to an embodiment of the invention can be placed in ablow moulding machine (not shown) and blow moulded according to bi-axialorientation blow moulding techniques with the neck 11 being held in amould in such a way as not to expand. Initially, the expandable portionof the preform below the neck can be mechanically stretched downwardlyto the bottom of the mould and then the bulk of the preform can be blownoutwardly by application of compressed air to the extent that a supportportion 18 is formed around the stem end 16 such that an enclosed area19 is formed between wall 20 of the container 10 and the stem 15 in theprocess of the formation by blow moulding of container 10.

In a particular form, the enclosed area 19 is of sufficientcross-sectional area to allow at least two fingers of a human hand to beinserted therethrough and to grasp handle 15 so as to support thecontainer 10.

The blow moulding operation is carried out in such a way so as toprovide a bottle or container having optimum strength by achievingbiaxial orientation of the molecules of the preferred PET material aswell as improved barrier properties to reduce oxidation.

In accordance with an embodiment of the invention, the neck 11 andhandle 15 can be crystallised by over-heating those parts of thepreform. The crystallisation of the handle increases its rigidity whichassists orientation of the preform and permits the use of less material.

Crystallisation of the neck and handle can be carried out by running hotoil over the neck and handle, applying an open flame or by blowing hotair.

The location of the handle 15 on the ring 14 ensures that there isminimum interference to the blow moulding process applied to theremainder of the preform. Either a one stage or two stage process can beused.

DETAILED DESCRIPTION OF FURTHER EMBODIMENTS

FIG. 1 illustrates the prior art preform or parison 21 of U.S. Pat. No.4,629,598. The concept of this prior art disclosure is to form a handleportion 23 from the locating ring of non-expandable portion 22 of theparison 21.

With reference to FIG. 2 and with reference to the detailed descriptionof the preferred embodiment this arrangement of FIG. 1 is modifiedaccording to the present invention in a number of respects.

Insets 2A, 2B and 2C show bulbous portions 27 forming part of stem end16 in the shape, respectively of a downwardly extending hook 24 a, abulb 24 b and an upwardly extending hook 24 c.

These portions have in common a shape which is adapted to engagemechanically with a blown portion of the container 10 which is adaptedto envelop the bulbous portion 27.

The process by which the second stage blowing of the expandable portion12 of parison 26 is effected so as to envelope the bulbous portion 27 ofstem end 16 is a stretch blow, biaxial orientation process.

With reference to FIG. 4 a particular method of manufacture of thepreform or parison 26 is illustrated. It includes a two stage processfor the formation of the parison by an injection moulding process. InStage 1 a first injection mould inlet 28 permits entry of plasticsmaterial for the formation of the expanded portion 12 of the parison 26(expanded in the blow moulding stage of container formation, withreference to FIG. 3).

In a second stage of the injection moulding process for the formation ofparison 26 a second injection mould inlet 29 permits entry of plasticsmaterial for the formation of the non-expandable portion 25 of parison26.

The two stage injection arrangement is such that different plasticsmaterials may be injected through first injection mould inlet 28 andsecond injection mould inlet 29.

In a particular form the plastics material injected in first injectionmould inlet 28 is non-recycled or substantially non-recycled plasticsmaterial whilst the plastics material injected into second injectionmould inlet 29 is recycled or at least partially recycled plasticsmaterial.

This arrangement permits controlled use of proportions of recycled andnon-recycled plastics material in order to achieve optimum economics inthe construction of parison 26.

In a modification of this arrangement the Stage 2 step can include theproduction of two walls in the non-expandable portion 25 comprisinginner wall 51 and outer wall 52. Inner wall 51 is made from virgin ornon-contaminated PET material and acts as an insulation barrier withrespect to wall 52 which can be made from recycled material 52. Thisdual wall arrangement can be produced by use of a sliding corearrangement as a modification in the die arrangement and processdescribed with reference to FIGS. 6, 7 and 8 later in thisspecification.

Of course the Stage 1 and Stage 2 steps of FIG. 4 can be interchanged inorder.

A parison and resulting container according to a further arrangement areillustrated in FIGS. 5A and B respectively. Like parts are numbered asfor previous embodiments.

In this arrangement the parison 21 includes a locating ring 14immediately below which is a first non-expanding region 30 and a secondnon-expanding region 31. The first non-expanding region 30 may itself beformed so as to be slightly raised or otherwise differentiated from theexpandable portion of parison 21. Second non-expanding region 31 may notbe differentiated from the expandable portion of parison 21 but, in use,the blowing operation will be such as to ensure that the secondnon-expanding region 31 is not expanded in the blowing process.

In this case the stem 15 includes a first rib 32 integrally moulded withand extending from locating ring 14. The stem 15 also includes secondrib 33 integrally moulded with and extending from second non-expandingregion 31. Stem 15 further includes a rib connector 34 integrallymoulded with and extending from first non-expanding region 30 andforming a continuous connection between first rib 32 and second rib 33throughout the length of stem 15.

The parison 36 of FIG. 5A is then blown in the manner previouslydescribed to form the volume 35 of container 37 illustrated in FIG. 5B.The neck portion including stem 15, ring 14, first non-expanding region30 and second non-expanding region 31 remain unexpanded whilst theexpandable portion 36 of parison 36 is biaxially stretched to form themajor volume 35 of container 37. The stem end 16 may include the bulbousportions according to the previously described embodiments forconnection to container 37 or, either alternatively or in addition caninclude the application of an adhesive material whereby a chemical bondis formed between stem end 16 and the wall of container 37 by the use ofa chemical intermediary.

In a modification of the arrangement of FIG. 5A and FIG. 5B firstnon-expanding region 30 and second non-expanding region 31 can form partof a single non-expanding region.

In yet a further modification second non-expanding region 31 can belocated, in the temperature transition zone of the container and whereinminor expansion during the blow moulding step may take place.

In yet a further modification both first non-expanding region 30 andsecond non-expanding region 31 may be located in the temperaturetransition zone immediately below the locating ring 14 and, again, minorexpansion of these regions may take place during blowing.

With respect to the last two variations described advantage is taken ofthe observation that expansion at the temperature transition zone can belimited by appropriate mould design and process control whereby unwanteddistortion effects caused by the rigid interconnection of thistemperature transition zone 30, 31 via second rib 33 and rib connector34 to ring 14 (or other non-expanding portion of the neck 11) can becontrolled.

In use preforms and containers blown therefrom can be manufactured asfollows:

A preform is formed from orientable plastics material, preferably PET orlike material in an injection moulding process. Slidable dies areillustrated in FIGS. 6, 7 and 8 and include a sliding core 40, slidingblocks 41, body 42, base 43, push block 44 and splits holder 45. FIG. 6illustrates the die in open position, FIG. 7 illustrates the die inclosed position and FIG. 8 illustrates a side view showing accommodationof the stem 14.

The completed preforms in a second and preferably separate step aresubsequently passed to a stretch blow mould machine where the preformsare first reheated to the appropriate transition temperature (referintroduction). The non-expandable portion of the preform includinglocating ring 14 and stem 15 are shielded substantially from the reheatprocess by appropriate guarding. In most instances there is likely to bea temperature transition zone in the region 30, 31 described withreference to FIGS. 5A, 5B.

The reheated preform is then placed in a mould and biaxially stretchedand the expandable portion blown to full size utilising processes knownin the art. During this process the preform is supported at neck 14 andmay also be supported at stem 15. Stem 15 does not take part in the blowprocess although its stem end 16 may be partially enveloped by anexternal wall of the blown container.

DETAILED DESCRIPTION OF METHODS OF MANUFACTURE INCORPORATING MODIFIEDTWO STAGE STRETCH BLOW MOULDING MACHINES

FIG. 9 illustrates a modified two stage stretch blow mould machine 110adapted to the stretch blow moulding (including biaxial orientation) ofthe preforms of previous embodiments and preforms of further embodimentsto be described below with reference to later figures. These preformshave been previously injection moulded as described, possibly in aremote location from the present machine.

The machine 110 comprises a first carousel 111 adapted to receiveintegral handle preforms 112 from inclined chute 113 into apertures 114spaced around the periphery thereof.

As first carousel 111 rotates it moves, via apertures 114 the preforms112 from the chute 113 to a second carousel loading position where thepreform 112 is transferred to a spindle 115 mounted near the peripheryof second carousel 116.

A sector of approximately 270° of second carousel 116 is arranged as apreheating tunnel 117 where the preforms 112 are progressively heated bya heating bank mounted in opposed relationship to the path of travel ofthe preforms.

The suitably preheated preforms 112 are loaded consecutively intoapertures 119 of a third carousel 120 which acts as a transfer mechanismto both suitably orient the preforms 112 about their longitudinal axisand present them to a mould cavity 121 comprising first half mould 122and second half mould 123.

It should be noted that during their time in the preheating tunnel 117the preforms 112 are rotated about their longitudinal axis by spindles115 and have a handle shield 124 mounted over the preform stem whichsubsequently forms a handle for blown container 125. Details of therotation of spindles 115 and the shielding of the preform stem arediscussed more fully with reference to FIGS. 10, 11 and 12.

Mould cavities 121 are mounted on the periphery of a fourth carousel126. During their travel through approximately a 270° sector the halfmoulds 122, 123 rotate to a closed position about their axis 127 and,whilst closed, the preform 112 enclosed therein is blown and biaxiallystretched in known manner in order to produce an integral handle, blowncontainer 125. This container 125 is ejected as illustrated when thehalf moulds open preparatory to receiving a fresh, preheated preform112.

With reference to FIG. 10 further detail is shown of spindles 115 andhandle shields 124 and their manner of operation upon and in relation topreforms 112 whilst passing through preheating tunnel 117 on secondcarousel 116.

The spindles 15 are rotated by band drive 128 so as to, in oneembodiment, rotate the preforms 112 through approximately four fullaxial rotations during their passage through the preheating tunnel 117.

Whilst in the preheating tunnel 117 a handle shield 124 is lowered overthe free end 129 of handle stem 130 so as to fully shield the handlestem 130 as best seen in greater detail in FIG. 12.

The shield 124, in one preferred form, is cylindrical save for a flutedopen mouth 131 best seen in FIG. 12. The fluted mouth 131 assists inensuring maximal shielding of handle stem 130 and also assists inguiding the shield 124 onto the free end 129 of stem 130.

Lifting and lowering of the shield 124 is effected through a shieldsupport stem 132 which is suspended from a cam follower 133 adapted totravel on cam 134.

The stems 132 are themselves rotated, by band drive 135 so as to followthe rotation of spindles 115. As best seen in end view of FIG. 11 theshield support stem 132 is offset from the cam follower stem 136 byvirtue of being mounted near the periphery of platten 137.

As cam follower 133 rides up cam 134 it pulls handle shield 124 up withit by virtue of the connecting link comprising shield support stem 132,platten 137 and cam follower stem 136.

Cam follower stem 136 can comprise a telescoped arrangement allowingrelative axial rotation between two component, telescoping partsthereof.

The handle shield 124 can comprise alternative shapes other thancylindrical, for example an oval cross section is possible although thecylindrical arrangement having a circular cross section is preferred.

The handle shield 124 is preferably made of insulating material such asa ceramic material and is covered on an exterior surface 138, in apreferred version, with a heat reflecting material which, ideally, isalso light reflecting.

In use the reflective surface 138 causes light and heat emanating fromheating bank 118 to be reflected thereof whereby two functions areperformed. The first function involves protecting the handle stem 130from heat. The second function is to reflect heat and light in thedirection of that portion of the preform closest to the handle stem 130so that it is evenly heated and tends not to be shadowed by the stem130.

In one particular form the handle shields 124 can be cooled by an air ornitrogen blast (not shown) directed at them whilst they are lifted clearof the preform 112. This will assist to prevent radiated and/orconvected heat building up within, the cavity 139 of the shield 124.

FIGS. 13-23 illustrate details of a preform, mould and container blowntherefrom and therein by the machine of FIG. 9. With reference to FIG.13, in a preferred version, dimension A is greater than dimension Bthereby to discourage tangling of preforms prior to loading into chute113.

It will be observed that the top end of the handle is located close tothe locating ring in this version. It will also be noted that the stemof the preform which subsequently constitutes the handle of the blowncontainer is fully supported within the half mould during the entireblowing process. In contrast the walls of the container includingportions of the container wall peripherally opposite the top end of thehandle stem are free to be blown within the constraints of the mould.

With reference to FIGS. 24-34 a second version of a preform, mould andresulting blown container is illustrated wherein first non-expandingregion 30 is relatively long in the axial direction including a portion140 which extends from locating ring 141 down to and around at least atop portion of the connection of the handle stem 130 thereby forming ajoin of the top end of handle stem 130 to locating ring 141. (Best seenin FIG. 24).

In this version there is at least partial expansion of wall portions ofthe preform located peripherally away from the join of the handle stem130 to the preform 112 (best seen in FIGS. 32 and 34). This expansion,relatively, is not as great as the biaxial expansion occurring below thefirst and second non-expanding regions 30, 31. It can, however, besignificant in providing strength and resistance to gas permeation in atleast second non-expanding region 31, if not non-expanding region 30.

Container Resistant to Internal Pressures

With reference to FIGS. 35 to 39 there is shown a container 150incorporating an integral handle 151 which is biaxially blown from thepreform 152 illustrated in FIGS. 40 and 41.

In this instance, as perhaps best seen in FIG. 36, the blown container150 includes a discontinuity region 153. In this instance thediscontinuity region 153 extends the entire circumference of thecontainer 150.

As best seen in FIG. 38 the discontinuity region 153 lies in a planewhich subtends an acute angle alpha with a horizontal plane XX.

The plane of the discontinuity region 153 is oriented so that where itpasses closest to the integral handle 151 it lies between first end 154and second end 155 of the handle 151.

In this instance that part of the discontinuity region 153 locatedfurtherest from the handle 151 lies in the plane XX which passesthrough, or close to, join region 156 where the second end 155 of handle151 is joined to container 150.

The discontinuity region 153 is formed by a substantial change indirection of the wall of the container 150, perhaps best seen in FIG. 35wherein first tangent 157 to upper wall portion 158 intersects withsecond tangent 159 to lower wall portion 160 of container 150 at anobtuse angle beta, thereby forming a portion of the discontinuity region153.

This discontinuity region 153 imparts additional strength to thecontainer walls, thereby to resist deformation of, particularly frominternal pressures which can arise when the container is sealed, as forexample when the container contains a carbonated beverage.

In order to assist in the creation of the discontinuity region 153 thepreform 152 from which the container 150 is biaxially blown includesdifferent wall thickness profiles, in this instance in the form of firstwall profile 161, second wall profile 162 and third wall profile 163separated one from the other by first transition zone 164 and secondtransition zone 165 as best seen in FIG. 40.

It will be observed that the wall thickness of third wall profile 163 isgreater than the wall thickness of second wall profile 162 which, inturn, is greater than the wall thickness of first wall profile 161.

The second end 155 of the handle 151 is joined to the container during abiaxial blowing operation by defamation and envelopment about the secondend 155. The second end 155 can include a bulbous portion including abulbous portion of the types illustrated in FIG. 2.

The preform 152 can be manufactured from PET materials in an injectionmoulding operation as described earlier in this specification.

The preform 152 is then blown as a second stage operation in a stretchblow moulding machine so that its walls conform to the inside surfacesof a mould, also as described earlier in this specification.

Tag Connected Handle

With reference to FIG. 42 and FIG. 43 an alternative version of thecontainer and the preform from which it is constructed are illustratedand comprises a rudimentary form of the multiple integral connectionhandle arrangement of the invention.

With reference to FIG. 42 the container 201 includes an integral handle202 as previously described and constructed, save that the connection tothe lower end of the container 201 is formed as an integral connectionby way of a tag 203 which extends from a lower edge 204 of a wide partof the handle 202 down to a mid circumferential portion 205 of container201 at which point it is integrally connected thereto. The lower edge204 of the wide part of the handle 202 includes a landing portion 206which merely rests on the surface of the container 201 at this pointrather than being integrally connected thereto or otherwise connectedthereto at this point.

A preform 207 from which the container 201 of FIG. 42 is blown isillustrated in FIG. 43. This preform 207 is constructed substantially inthe same manner as that illustrated in FIG. 40 except that lower edge204 of handle 202 is integrally connected to the preform 207 by way oftag 203 in the manner illustrated in FIG. 43.

The preform 207 is blown to form the container of FIG. 42 utilising theprocess previously described with reference to FIGS. 10, 11 and 12.

Preform and Container with Multiple Integral Connection Handle

With reference to FIG. 44 there is shown a preform 301 having a neckportion 302 and an expandable portion 303 located therebelow.

In substitution for the stem of the earlier examples in thisspecification is a loop 304 made from the same material as the wall 305of the preform 301. In this instance the loop 403 is integrallyconnected at a first end 306 to a first location 307 on and forming partof the wall 305.

The other of the loop 304 being second end 308 is integrally connectedinto wall 305 at second location 309.

The loop 403 is formed in the same mould as and at the same time as thepreform 301 is moulded, in a preferred form from PET plastics material.

In this instance and with reference to FIG. 47 the loading of plasticsmaterial in the region of the wall 305 subtended between first location307 and second location 309 can be differentially controlled as afunction of location on the circumference of the wall 305 in this regiondesignated the differential loading region 310 in FIG. 47.

In this particular instance there is an increased loading of material inthe region of 310 immediately between the first location 307 and secondlocation 309 whilst, the opposite region 311 located diametricallyopposite region 310 has material removed from it as indicated in dottedoutline.

Differential material loading as a function of circumferential positionon wall 305 aids in providing control over the wall thickness of theblown container 312 illustrated in FIG. 45.

The container 312 can be blown in a two stage process utilizing theapparatus previously described in this specification and utilizing theshielding principals also described.

In this example the region 310 subtended between first location 307 andsecond location 309 remains substantially unchanged during the blowingprocess and can be considered an extension of and part of the nextportion 302 of the preform 301.

FIG. 346 illustrates an alternative form of construction of a loop 313which, in this instance, again comprises an elongate, stem-likestructure including reinforcing ribs 314 but having, in this instance, adeflectable portion 315 which is connected on one side by a first bridgeportion 316 to the balance of the loop 313 and, at its other end by asecond bridge portion 317 integrally to container wall 318.

In this instance the second bridge portion 317 is akin in structure tothe tag 203 previously described and provides a necessary element offlexibility. A first bridge portion 316 can be of the same kind ofstructure and, again, being integrally formed at the time that thepreform is blown.

In use, during a second stage blowing of the container 319 it will beobserved that the container wall 318 to which second bridge portion 317is integrally connected moves during blowing and this movement isaccommodated by deflection of deflectable portion 315, loop 313 aboutfirst bridge portion 316 and second bridge portion 317.

In production, utilizing the apparatus previously described, it ispossible to move material differentially within a wall portion such as,for example, in the differential loading region 310 it is possible tocause the material closest to the inside of the container to move whilstleaving the material closest to the outside of the container essentiallystatic relative to first location 307 and second location 309, therebyleaving the outside wall region stable during the second stage blowingstep.

In production in a two stage machine it is important to have a heatingtunnel of sufficient width to allow for rotation of the preforms withstem/loop protecting thereon. It is also important to have the abilityto shield in a controllable manner the stem/loop portions of the preformduring its pass through the heating tunnel and also the ability toselectively shield that region of the preform wall subtended between andbeneath the stem/loop thereby to provide an important element of controlover the heat profile throughout the preform immediately prior to itsinsertion into the mould cavity for the second stage blow moulding step.

In a particular form the heat shield can be attached to a mandrel andcan pass into the mould cavity for retention therein during the secondstage blowing step.

Whilst a single handle has been shown on embodiments described thus farit will be appreciated that more than one handle can be provided on agiven container following the principals described in thisspecification.

A preform 410 according to a further embodiment of the invention isillustrated in side section view and, in this instance, includes asymmetrical thickening of the wall 411 of the preform 410 in the lowerregion 412 which extends from immediately below the point of connection413 of the lower end 414 of handle 415. In a second, intermediate region416 located between point of connection 413 and point of connection 417of handle 415 the wall thickening of the preform 410 tapers graduallyfrom first thickness T1 to second (thinner) thickness T2.

This thickening is symmetrical about the longitudinal axis TT of preform410 and results in a controllable increase in the thickness of materialin blown container 418 (refer FIG. 50) in the corresponding intermediateregion 416, but also in a sub-region 419 immediately below point ofconnection 413 of the lower end of handle 414. It is postulated that theincreased thickening of the blown container in the region 419 resultsfrom a flowing of the material from intermediate region 416 through tosub-region 419 during the second stage process of blow moulding, therebyto provide control over the wall thickness of material in the region 419of the blown container 418.

FIGS. 51 and 52 provide alternative views of the blown container 418.FIG. 51 illustrates more clearly the anti-symmetric bulbous portion 420which is offset about the longitudinal, axis TT with respect to handle415.

FIG. 52 illustrates a star formation indentation 421 in base portion 422of container 418. It comprises a central, circular indentation 423 fromwhich subtend wedge shaped indentations 424 in a circular array asillustrated in both FIG. 50 and FIG. 52.

In this instance container 418 also includes longitudinal indentations425 in the walls of region 412 as illustrated in FIG. 50, thereby toincrease the strength of the blown wall portions in this region.

Second Preferred Embodiments of Modified Two Stage Process

In accordance with a second series of preferred embodiments of theinvention a stretch blow moulding machine 510 as illustrated in FIG. 55is utilised to stretch blow mould a PET resin preform 511 as shown inFIG. 53 so as to produce an integral handle container 512 as illustratedin FIG. 54. The preform 511 and resultant container 512 are of a typeillustrated in and described in co-pending patent applications to thesame applicant including PCT/AU98/01039.

First Preferred Embodiment of a Second Stage of a Two-Stage Process

In one preferred form, a stretch blow moulding machine 510 of FIG. 55includes a chain drive transport mechanism 513 which has a plurality ofmandrels 514 mounted thereon at substantially equally spaced intervals,such that each mandrel follows a generally oval path through variousprocessing stations on the machine 510.

A preform 511 mounted on a mandrel 514 proceeds from loading station 515to heating station 516 to stretch blow moulding station 517 and thenceto unloading station 18.

As illustrated in FIGS. 56 through to 60 each mandrel 514 includes anesting shield 519, a perspective view of which is shown in FIG. 61.

The nesting shield 519 is adapted to receive within it handle stemportion 520 of preform 511 for the purpose of shielding handle stemportion 520 against heat imparted by radiant heaters 521 as the preformis transported through the heating station 516 in the directionindicated by the arrow in FIG. 55.

As the preforms 511 are transported through the heating station 516 theyare rotated on mandrels 514 by second chain drive 522 acting on atoothed peripheral portion (not shown) of each mandrel 514. Rotation ofthe mandrels 514 is effected by reason of the speed of rotation of chaintransport drive mechanism 513 being different from the speed of rotationof second chain drive 522.

At the time of entry into blow moulding station 517 each preform 511 israised proud of top portion 523 of mandrel 514 in order to permitengagement of cavity portions of die halves 524 around base step portion525 of handled step portion 520 and preform neck ring 526.

It is to be noted that the die halves 524 include indentation 527adapted to receive nesting shield 519 therewithin when the die halves524 have come together thereby to house and protect the nesting shield519 against damage during the blow moulding stage. During blow mouldingthe preform 511 is biaxially stretched by stretch rod 528 and theinjection of gas (not shown) into the interior of the preform 511whereby it conforms to the shape of the mould cavity to form container512.

The die halves 524 then open and chain drive transport mechanism 513,temporarily stopped during the blow moulding process is caused to rotateagain so as to present blown containers 512 at unloading station 518 forremoval therefrom by forks 529.

With reference to FIG. 62 there is shown a perspective view of a 16cavity preform mould 610 adapted to be seated in an injection mouldingmachine (now shown) which injects PET 611 (or like orientable plasticsmaterial) through injection nozzles 612 (refer FIGS. 70, 71) intopreform shaped cavities 613 formed when the dye is in closed condition,as best seen in FIGS. 66 and 67. The dye cavity is then opened causingthe splits 614, 615 to be forced apart by cams 616 thereby permittingejection of the handled preforms when sliding cause 617 are withdrawn,as best seen in FIG. 69.

The injection stage typically takes between 45 seconds and one minute ona 500 tonne injection machine allowing the production of 16 preforms atone time during this time period.

In accordance with the modified two stage process the preforms 511,after ejection, are allowed to cool and cure for at least 6 hours beforeplacement in the blow moulding machine described and shown withreference to FIGS. 55 to 61. Ideally the preforms are allowed to cool toroom temperature during this time and, most preferably, are allowed tocure for at least 24 hours prior to introduction to the blow mouldingmachine in order to ensure consistency of structure of the preforms and,hence, consistency of blowing in the critical second stage.

A typical production rate for the blow moulder described in FIG. 55onwards is of the order of 1500-2000 blown containers per hour thusmatching the production rate of the 16 cavity preform mould.

Second Preferred Embodiment of a Second Stage of a Two-Stage Process

With reference to FIGS. 72 to 77, in a further example of a second stage700 of a two-stage process, previously injection moulded preforms 712proceed through the following stages:

2. handle orientation,

3. transfer to transport support,

4. rotation through heat conditioning,

5. blow-moulding.

Handle Orientation

The body portion 730 of preforms 712 must be heated to the requireddegree of plasticity so that the material in the body 730 of the preformcan be bi-axially oriented in the stretch-blow-moulding process.However, neither the neck portion 729 nor the handle 713, should besubjected to bi-axial stretch blow moulding and must be shielded fromexcessive heat during the heating stage to prevent their crystallizationwith consequent loss of strength. Thus for transport through the heatingstage 718, the handle 713 of the preform 712 is protected by a shield758, and the neck portion 729 by a cylindrical socket 761, as shown inFIG. 76.

The orientation of the handle must be controlled at a point prior to theentry of the preform into the heating stage to enable the heatprotective shield 758 to be correctly fitted over the handle 713 of apreform 712. Furthermore, it is essential that each preform 712 ispresented to the moulding tool 720 with the handle correctly oriented sothat the handle is correctly enclosed in the halves of the mould whenthis closes for the blowing stage.

With reference to FIGS. 72 and 73, in one preferred form, preforms 712are fed from a suitable supply source, such as for example a hopper or avibratory bowl 722 to an infeed rail 724 at loading station 714. Infeedrail 724 is arranged so that preforms 712 progress along rail 724,either by gravity, vibration or other linear transporting means,supported between parallel rail elements 725 and 726 at the underside oflocating ring 728, as shown in FIG. 73.

The orientation of the handles 713 of the preforms during transportalong infeed rail 724, is preferably controlled by a guiding channel(not shown) to loosely constrain the handles from assuming anorientation approaching, or at right angles to the direction of travel.Preforms 712 are thus constrained to proceed along infeed rail 724either with the handle 713 pointing generally forward of the body 730 ortrailing it. An escapement (not shown) at the end of infeed rail 724provides for control of sequential discharge of individual preforms 712from the end of the rail.

As shown in FIGS. 73 and 74, preforms thus released from infeed rail724, are allowed to drop vertically into an orienting apparatus 732fixed directly below the end of infeed rail 724. In a preferred form,the orienting apparatus 732 shown in FIG. 73 consists of a truncatedcylindrical sleeve 734 which has an internal diameter adapted to allowfree sliding passage of the cylindrical body 730 of the preform andlocating ring 728. The wall of the sleeve 734 is provided with a slit736 extending the length of the sleeve 734 from a handle inlet opening738 at the upper edge 749 of the sleeve 734, to a handle outlet, opening740 at the lower edge 741. The slit is of sufficient width to allowsliding passage of the handle 713 of a preform 712.

The upper edges 745 and 743 of sleeve 734 are formed to guide a handle713 into the slit 736. For this purpose the upper edges 745 and 743 areformed to slope steeply from respective high points 744 and 744Adiametrically opposite the handle inlet, down to the handle inletopening 738 of slit 736. To ensure that the handle does not fall ontoand become lodged on the highest points on upper edges 743 and 745, theinfeed rail 724 is arranged approximately at right angles to the radialposition of slit 736. Thus handles 713 which, as described above areprevented from assuming this orientation while conducted along theinfeed rail 724, cannot contact the upper edges 743 and 745 at thehighest points, but will rather drop onto the orienting device with thehandle contacting either sloping upper edge 743 or 745.

Sloping edges 743 and 745 slope down to respective sides of the slit736, from the highest points 744 and 744A, ending in respective smoothlyrounded corners 748 and 749 at the handle inlet opening 738. The slopeis sufficient to ensure that the handle 713 of the preform 712 slidesalong the sloping edge sections.

A preform 712 falling into the apparatus 732 with a handle 713 notaligned with slit 736 will, as the handle makes contact with eithersloping section 743 or 745, be rotated as it slides down under its ownweight, until handle 713 is aligned with slit 736 and the preform 712falls cleanly through the apparatus.

Transfer to Transport System and Heating Stage

FIG. 74 shows a section of the handle orientation and transfer to theheating stage of one preferred form of a blow moulding machine. Asdescribed above, a preform 712 is shown falling into the orientingapparatus 732.

Arranged immediately below apparatus 732 is an indexing table 750provided around its periphery with a number of equally spaced nests 752,so situated that each successive nest 752 comes to an aligned positionwith the axis of apparatus 732 at each indexing of the table 750. Nests752 are adapted to receive a preform 712 and retain it in such a waythat the orientation of the handle 713 initially imposed by apparatus732 is maintained relative to each nest 752 for the duration of thepreform's retention in the nest. (Note all the nests shown in FIG. 74are empty.)

When, with the indexing of the table 750, a preform 712 reaches atransfer station 754, the preform is ejected upwardly out of the nest752 in which it was supported, to engage with one of a series ofmandrels 756 of the preform transport system 716, operating between theloading station 714 and the blow-moulding tool 720. A preferred mandrelarrangement with a preform attached is shown in FIG. 75.

When inserted into the mandrel, the open neck 729 of the preform 712 ispushed over a resilient plug 759 located in a cylindrical socket 761 atthe base of the mandrel. The plug 759 enters the open neck as aninterference fit sufficient for the weight of the preform 712 to besupported within the socket 761. The socket also acts to shield the neck729 from excessive heat during the heating stage.

Heating Stage

The proper preparatory heating of a preform 712 is critical to thesubsequent stretch blow moulding stage. The necessity to shield thehandle 713 of the preforms of the present invention complicates thecorrect distribution of the heat energy applied to the preform andrequires careful design of the heat shield 758 and the arrangement ofthe heating elements.

FIG. 76 is a more detailed sectioned view of a preform 712 fitted with aheat shield 758. The mandrel 756 and retaining means for supporting thepreform are not shown in this view for clarity. It will be noticed thatthe shield 758 for the handle 713 of the preform 712 is carefully shapedto protect the handle 713 yet allow heat energy from the heatingelements (shown in FIG. 77) to reach that region 770 of the body 730 ofthe preform lying between the upper and lower attachment points 772 and774 of the handle 713. The heat shield 758 comprises side portions 776(only one is visible in the sectioned view of FIG. 76) extendingsubstantially over opposing sides of the handle 713. The side portions776 extend from opposing edges of a spine element 778 which conforms toupper portions of the handle and which is attached to the mandrel socket761. The shield is open at the underside of the handle to allow for thepreform and its handle to be driven upwardly to engage with the mandrel,and subsequently, at the end of the heating stage to be withdrawn fromthe shield.

To ensure the optimum heat distribution, the sides 776 of the heatshield 758 have been shaped to leave a gap 780 to allow heat penetrationto region 770 as the preform is rotated during its transition throughthe heating stage. The size and shape of gap 780 are determinedempirically in combination with the optimal arrangement of the heatingelements 782 of the heating system as shown in FIG. 77.

With reference to FIG. 77, the heating system 718 comprises banks ofheating elements 782 supported at their outer ends by adjustable racks784 in a manner well known for preheating the preforms of conventionalsymmetrical containers.

In the present application however, the heating elements 782 arearranged in a pattern as shown in FIG. 77 and their individual intensityadjusted to take into account the handle and the particular energydensity required to ensure that all parts of the preform are heated tothe required degree of plasticity as the rotating preform 730 passesalong the banks of heating elements.

In a first alternative preheating arrangement (not shown), a preform ofthe present invention is again attached to a supporting mandrel forpassing through a heating stage. In this arrangement however, eachmandrel is provided with an elongate cartridge heater, coaxial with therotation axis of the mandrel and body portion of the preform, andextending substantially the length of the body portion of the preform.The preform is thus heated from the inside. The cartridge may be dividedalong its length into several individually controllable heating segmentsso that heating may be adjusted to suit any wall thickness variations ofthe preform body.

In a second alternative preheating arrangement (not shown), each preformis enclosed by two halves of a heating shroud as the preform enters theheating stage. The shroud is linked to a separate transport system whichdrives the shroud in synchronous movement with that of the mandrels. Atthe emergence of the preform from the heating stage, the shroud opensand the preform continues to transit to the blow moulding tool. Theshroud can be arranged to fit relatively closely to the body of thepreform, leaving the integrally attached handle substantially outsidethe shroud and thus protected from the preheating of the preform.

Rotation Through Heat Conditioning

To ensure even heating of the body 730, the preforms 712 must also berotated as they pass through the heating stage 718 past the banks ofheating elements 782 shown in FIGS. 72 and 77. A necessary feature ofthe mechanism driving this rotation is that orientation of the handle atthe end of the heating stage 718 must be such as to ensure that thehandle correctly enters the blow moulding tool 720. Two preferredarrangements for achieving this result are described.

First Example

Each mandrel 756 (shown in FIG. 75) includes a mounting 760 forattachment to the transport system 716. Transport system 716 maycomprise a twin-strand chain conveyor supported at each end by pairs ofsprockets, with the mandrels mounted at intervals between the chains.Bearings 762 within mounting 760, allow rotation of the preform 712 andits handle protecting heat shield 758.

A sprocket or toothed pulley 764 engages with a fixed rack or chain (notshown) of the transport system so as to induce rotation of the preformas it is carried past the heating stage 718. This rack or chain isarranged along the lower leg of the twin-strand conveyor, this being theleg along which the mandrels are carrying preforms through the heatingstage. To maintain the orientation of the mandrels both at the preformloading and unloading stages, the mandrels are provided with a guidingsurface which slidingly engages with a fixed rail, preventing rotation.The rack is of a length and number or teeth, which together with thepitch diameter of the toothed pulley 764, is designed to impart a wholenumber of rotations to the preforms so that the handle has the sameorientation when leaving the end of the rack as it first had afterinsertion at the preform loading point.

Second Example

The containers of the present invention may be successfully blow mouldedin suitably modified conventional blow moulding machines. Typically therotation of the preforms through the heating stage of these machines isnot adapted to ensure that preforms have any particular orientation atthe point where they enter the blow moulding tool. Preforms generallyare supported on a mandrel carriage travelling along a recirculatingrail system with a sprocket on the carriage engaging a chain or rack asthe carriage passes the heating banks, thereby inducing the rotation, ofthe preform. The sprocket, and hence the preform attached to thecarriage mandrel, are freely rotating when not in contact with therotation inducing system of the heating stage.

Typical also of conventional stretch blow moulding machines is that thetransport rail, and the carriage and mandrel assembly pass through theblow moulding stage, the blown container only being ejected off thesupporting mandrel when the container emerges from the moulding tool.The transport system moves incrementally, to allow the carriage (orcarriages in the case of a multi-cavity tool) to remain stationary whilein the moulding tool for the blowing cycle.

The present disclosure includes a means of controlling the orientationof the mandrels for moulding a container with integral handle of thepresent invention on such a conventional machine. The arrangementcontrols the orientation of the mandrels both at the fitting of thepreforms to the mandrels prior to entry to the heating stage and at theentry into, and transit through the moulding tool.

For this purpose each of the conventional carriages of a standardstretch blow moulding machine is modified or replaced with carriagesfitted with a spring-loaded locking pawl for engaging with a notchprovided on a boss of the carriage sprocket. The pawl is activated intopotentially engaging the notch and thus locking the sprocket, by a leverprojecting from the side of the carriage contacting a fixed cam or rampmounted adjacent the transport rail.

This activation occurs at a point on the transport rail prior to thecarriage and mandrel entering the moulding tool. At that point thesprocket is no longer in contact with the rotation driving system; thatis the sprocket is free to rotate. At the following incremental stop ofthe transport system after activation of the pawl, an electricallydriven friction wheel engages the sprocket, rotating it until the notchcomes into alignment with the spring-loaded pawl. The pawl engages thenotch, arresting the rotation of the sprocket. The mandrel is thencorrectly aligned for the mandrel and handle of the preform to enter thecavity of the blow moulding tool.

When the carriage emerges from the tool, the sprocket is still locked.The blown container is ejected from the mandrel and the carriageincrements to the loading station to accept a pre-oriented preform asdescribed above. Prior to the carriage re-entering the heating stage,the lever controlling the pawl is brought into contact with a secondfixed cam or ramp, which reverses the position of the lever, withdrawingthe pawl from the notch to allow the machines rotation system to controlthe rotation of the preform through the heating stage.

Blow Moulding

In the First Example described above, the preforms are ejected from theheating stage transport system mandrels onto a transfer system (notshown), which carries each preform into the blow moulding tool,retaining the orientation of the handle. In this arrangement the handleis nested in a separate cavity of the mould such as for exampleillustrated in FIG. 16. The same transfer system, which may comprise atwo-strand conveyor for example, also transfers the blown container (orcontainers) out of the moulding tool.

In the Second Example described above, in which the mandrels of aconventional but modified blow moulding machine, transit through themoulding tool with the preform, it is necessary to accommodate the heatshield in the mould tool. The heat shield shown in the example of FIGS.75 and 76, is fixed relative to the mandrel and so the cavity for thehandle must be sized to also accommodate the heat shield in its positioncovering the handle.

It is necessary however, that the upper and lower attachment points 772and 774 of the handle 713 be closely confined in the moulding tool toprevent their movement during the stretching and blowing operation. Thegaps between the body 730 and the heat shield 758 at the attachmentpoints 772 and 774 are sufficient to shield these portions of the handlefrom excessive heat but still allow suitable structures in the mouldingtool to engage and restrain the handle attachment points as the toolcloses. A more preferable arrangement includes a mechanism (not shown)to lower the preform relative to the heat shield by an amount sufficientto expose the upper attachment point 772 of the handle through thelarger gap 780 in the sides 776 of the shield 758. With the lowerattachment point 774 then located below the lower edge of the shield,this arrangement allows a better access of the restraining structures toconfine the handle.

In an alternative arrangement (see for example FIG. 58), the heat shieldis not rigidly attached to the mandrel socket 761 but is hinged to it.In this arrangement a mechanism incorporated in the moulding toolrotates the heat shield away from the handle as the tool closes so thatthe handle is closely nested by the tool. The heat shield is thenaccommodated in its own cavity, separated from that of both the handleand the final body shape of the container.

It should be noted that although the region of the preform body definedby a narrow strip between the two attachment points 772 and 774 ofhandle 713 remains substantially stable during the stretching andblowing of the container, both the regions of the outer and innersurface layers laterally away from this narrow strip are subjected tobiaxial stretching. Although the outer surface of the narrow stripremains substantially stable, the wall of the strip and the inner layersbetween the handle attachment points undergoes a degree of flow andthinning together with the surrounding regions as the plasticisedmaterial comes under the influence of the stretching and blowing forces.

It is important that those portions of the preform which are to besubjected to biaxial stretching and blowing, that is all of the body 730below the neck or locating ring 728, do not come into contact with thewalls of the moulding cavity until forced to do so when the process ofbiaxial orientation of the material of the preform is substantiallycomplete. For this reason the region between the two connection points772 and 774 of the handle is not initially in contact with the wall ofthe cavity when the tool has closed on the preform. Rather there isprovision of a slight gap between the outer surface of the preform bodyand wall of the cavity to ensure that no premature crystallizationoccurs (for example in a cooled tool) and that a degree of material flowand biaxial orientation, particularly of the inner layers of the regionbetween the connection points does occur.

The above describes only some embodiments of the present invention andmodifications obvious to those skilled in the art can be made theretowithout departing from the scope and spirit of the present invention.

INDUSTRIAL APPLICABILITY

Embodiments of the invention are applicable to the manufacture ofcontainers made from orientable plastics material and incorporating ahandle or like grasping fixture as an integral component of thecontainer.

1. An apparatus for controlling the orientation of an integrally formedhandle of a preform during a preheating stage of a stretch blow mouldingprocess; said apparatus including a mandrel provided with a shield forprotecting said handle from excessive heat during said preheating stage.2. The apparatus of claim 1 wherein said mandrel is one of a pluralityof mandrels attached to a twin-strand conveyor system; each said mandrelrotatably mounted between strands of said twin-strand conveyor.
 3. Theapparatus of claim 1 wherein said preform is inserted into said mandrelat a preform loading location such that said handle is located withinsaid shield.
 4. The apparatus of claim 2 wherein said conveyor systemextends between said preform loading location and a preform unloadinglocation.
 5. The apparatus of claim 1 wherein said heat shield is forthe protection of said integrally formed handle of a preform; said heatshield protecting said handle from excessive heat as a body portion ofsaid preform is pre-heated prior to entry into a stretch blow mouldingtool.
 6. The apparatus of claim 5 wherein said heat shield is attachedto a mandrel of a preform transportation system; said heat shieldadapted to at least partially enclose said handle.
 7. The apparatus ofclaim 5 wherein said shield comprises side portions extendingsubstantially over opposing sides of said handle; said side portionsextending from opposing edges of a spine element attached to saidmandrel; said spine element conforming to upper portions of said handle.8. A mandrel for support and selective heat shielding of a preformprovided with an integral handle; said mandrel comprising a verticallyoriented socket portion and a shield portion depending from said socketportion.
 9. The mandrel of claim 8 wherein said socket portion isadapted to accept insertion and retention therein of a neck portion ofsaid preform; said shield portion adapted to accept insertion and atleast partially shield said integral handle.
 10. The mandrel of claim 8wherein said socket portion is provided with a resilient plug; said plugadapted to enter an open neck of said preform when an inverted saidpreform is urged upwardly to engage with said mandrel; said plugentering said open neck as a friction fit sufficient to support theweight of said preform.
 11. A method for controlling a preform forstretch blow moulding a container with an integrally formed handle; saidpreform comprising a body portion and said integrally formed handle;said preform transferred from a preform supply source to a blow mouldingtool for blowing said container; said method including the steps of: a.passing said preform through a preform handle orienting apparatus, b.transferring said preform to a preform transportation system, c.transferring said preform from said transportation system to said blowmoulding tool; and wherein said method includes the further steps of: d.maintaining orientation of said preform handle imposed by said handleorienting apparatus during said transfer to said preform transportationsystem and said transfer to said blow moulding tool, e. rotating saidpreforms during transport along said transportation system past an arrayof preform heating elements, f. shielding said integrally formed handlesfrom excessive exposure to heating from said heating elements.
 12. Amethod as claimed in claim 11 for preheating a preform; said preformcomprising a body portion and an integrally attached handle; said methodincluding the steps of: a. orienting said preform so as to engage saidpreform with a transport system mandrel; said mandrel provided with ashield substantially covering said handle, b. arranging banks of heatingelements into a pattern allowing for rotation of said handle and saidshield, c. setting heat outputs of individual heating elements todeliver a required distribution of heat density to said body portion ofsaid preform, d. rotating said preform during a preheating stage as saidtransport system carries said preform past said banks of heaterelements.